Bosch Wideband Air/Fuel ratio sensors utilize a more sophisticated sensing element that enables them to produce a precise output in proportion to the air/fuel ratio. As a result, a wideband A/F sensor measures exhaust gas oxygen accurately from as rich as 9.0:1 to as lean as free air. The use of the Wideband A/F sensors is growing rapidly as original equipment in vehicles and in high-performance specialty markets.